Parathyroid Hormone (PTH), Intact

Parathyroid Hormone, Intact

Alternate Test Name

PTH

Intact PTH

Epic Mnemonic
Sunquest Mnemonic

LAB813
IPTHB

Category

Chemistry

Methodology

PTH: Electrochemiluminescence immunoassay 

Test Performance Schedule

Monday - Friday

Result Availability

Within 24 hours

Container

Gold top (SST) or Red top (serum) tube

Volume

Pref. Vol.: 1.0 mL serum
Min. Vol.: 0.5 mL serum

Collection Instructions

• Routine venipuncture

• Immediately after collection, gently invert tube 5-10 times

• Clot 30 minutes

• Promptly centrifuge 10 minutes

• If no gel barrier is present immediately transfer serum or plasma to a plastic tube and refrigerate

• Properly centrifuged gel barrier tube does not require transfer of serum or plasma to separate tube

Transportation Instructions

Refrigerated

Stability

• Room Temperature: 8 Hours

• Refrigerated: 2 Days

• Frozen: 6 Months

Causes for Rejection

• Samples collected in a Purple top (EDTA) tube
• Hemolysis

Remarks

Medicare Medical Necessity Policy

Biotin, also referred to as Vitamin B7 or Vitamin H, can interfere with this test when taken in mega doses of 5mg (5000 mcg) or more. It is often promoted as a skin and hair beauty aid. Please ask your patients to refrain from taking Biotin or supplements containing Biotin for at least 24 hours before collecting specimens for lab testing.

https://biotinfacts.roche.com/

https://www.fda.gov/medicaldevices/safety/alertsandnotices/ucm586505.htm

CPT Codes

83970

Effective/Revised

7/29/2020

Parathyroid hormone (PTH) is formed in the parathyroid glands and secreted into the blood stream. Selective measurement of the (mainly) intact parathyroid hormone permits direct ascertainment of the secretory activity of the parathyroid glands. PTH, together with vitamin D and calcitonin, brings about mobilization of calcium and phosphate from the skeletal system and increases the uptake of calcium in the intestine and the excretion of phosphate via the kidneys. The constancy of the blood calcium level is ensured by the interaction of PTH and calcitonin. The secretion of PTH is inhibited by high calcium concentrations and promoted by low calcium concentrations. Parathyroid gland disorders lead to elevated or depressed blood calcium levels (hypercalcemia or hypocalcemia) brought about by a change in the secretion of PTH.

Hyperfunctioning of the parathyroid glands results in an increased secretion of PTH (hyperparathyroidism). Primary causes are adenomas of the parathyroid glands. In secondary hyperparathyroidism the blood calcium level is low as a result of other pathological states (e.g. vitamin D deficiency).